Efrotomycin is produced by the extraction of a fermentation broth of Streptomyces lactamdurans. The compound, the microoganism and the method used to obtain it are disclosed in U.S. Pat. No. 4,024,251 to Maise et al. Efrotomycin has the following structure: ##STR1##
Efrotomycin is a Gram positive and Gram negative active antibiotic and antimicrobial agent and is useful as a growth promotant in domestic animals.